The objectives of the program are to identify non-histone chromosomal proteins influencing tumor growth using transplanted hepatomas as a model system. In this study, hepatomas showing a spectrum of growth rates will be used in order to correlate changes in non-histone chromosomal proteins with tumor growth rate. An attempt will be made to discriminate between transformation-linked and progression-linked alterations in hepatomas. Further purification will be performed of those proteins whose concentration has been shown in our preliminary studies to be changed in liver tumors. Particular attention will be directed to proteins subject to phosphorylation, and correlations between phosphate content and turnover and the rate of cell division will be investigated. In order to test the potential regulatory properties of isolated proteins, their influence on DNA structure and function will be examined. Structural changes will be followed in circular dichroism studies and effects on function will be tested by action on DNA replication and transcription. The potential of proteins, which are either increased or decreased in amount in hepatomas, to exhibit contrasting proterties in these test systems will be investigated.